Can you help with a punnets square question?

Question

When crossing RR with RR, the resulting gamete would be RR, right? and what about RR and PP. Would it be RP? They are all dominant so I don't know. Or do you use all four alleles for the resulting gamete and am I even using allele and gamete in the right context? So would it be RRRR and RPRP(RRPP)?

Ok so I have a question about this answer...RR+RP will result in 2 RR's and 1 RP.

When I am at the box where I enter the information, I should only have two alleles right? I mean it doesn't usually work out that you have different about's of alleles in different gametes on one punnet square, does? So how would this answer be written in?

It's for a pea plant. The R and P are dominant alleles. Round seed shape and Purple flower color.

Answer 1

Make a key for the letters you will use. A key will help you keep everything more clear.

R=round seeds
r = wrinkled seeds
P=purple flowers
p=white flowers

"Alleles" are different forms of a gene for a trait. So in your problem, the gene for seed shape has two alleles: R and r. The gene for flower color has two alleles: P and p.

"Gametes" are the reproductive cells made by the parents. Each gamete will contain one allele for each trait (one of the Ps and one of the Rs).

The parents and the offspring will have two Rs and two Ps, whether you use the capital letters or lower case letters.

Parents: RRPP crossed with rrpp
Gametes from first parent: RP, RP, RP, RP
Gametes from second parent: rp, rp, rp, rp

You can put those gametes all on a Punnett square, but there's no point in doing that when all the offspring will be alike. Each offspring gets RP from one parent and rp from the other parent. So each offspring is RrPp.

To get the F2 generation, we cross two of the F1 offspring. That's the same idea as letting them self-fertilize which is what Mendel did.
Cross RrPp with RrPp
Gametes from first parent: RP, Rp, rP, rp Write these on the left side of a Punnett square that has 16 boxes.
Gametes from second parent: RP, Rp, rP, rp Write these on the top of the Punnett square.

Fill in the boxes using the letters from the far left and the letters from the top of the column.
First row of boxes in the Punnett square will be RRPP, RRPp, RrPP, RrPp. All four of these are round, purple.
Continue with the other boxes. You will find that the offspring are expected to be in this ratio ...
9 round, purple: 3 round, white: 3 wrinkled, purple: 1 wrinkled, white

So ...
-- Gametes get one letter for each trait (ex: rp, Rp, ...)
-- Parents and offspring have two letters for each trait (ex: RrPp, Rrpp, ...)

Answer 2

I'm afraid your question is kind of confused, and so is hard to answer. It depends on whether R and P are alleles (different forms of a single particular gene, like purple flowers in peas), or if they are different genes. If they are alleles, usually only one is dominant. If they are co-dominant, then a cross between an RR individual and a PP individual would produce offspring that are all RP, and would probably show a combination of the traits. (For example, Red and White flower colors in tulips are co-dominant. An RR individual is red, a WW individual is white, and a RW individual is pink.)
If R and P are genes on different chromosomes, then an individual who was homozygous for both (RRPP) could only produce gametes with RP. If however, the parent was heterozygous (RrPp), then four types of gametes could be produced: RP, Rp, rP, or rp.

Answer 3

That would depend on whether R and P are alleles for the same gene.

If they are then you will get RP.
In this case, it could be either codominance or incomplete dominance.

If they are not alleles of the same gene, then it's a case of linked genes. in this case, you have to write RRPP as R and P code for different characteristics.

Answer 4

You're correct. When crossing RR with RR, the result is another RR. RR+RP will result in 2 RR's and 1 RP.

Answer 5

yes it would be RR, but RR and PP would be co-dominent. i think.I am in life science in the 7th grade and we went over that stuff the 2nd nine weeks. like if a white bunny and a black bunny have offspring the offspring would be black and white.i am not sure how to wright it though. i learned it a long time ago and forgot most of it.

Answer 6

im learning about punnett square right now and im so confused too!